The objective of this supplemental project is to increase the scope of National HIV Behavioral Surveillance (NHBS) to include surveillance of young men who have sex with men (YMSM) between 13 and 17 years of age as a focus area in an on-going surveillance system. The New York City Department of Health and Mental Hygiene (DOHMH) proposes to conduct a pilot study of HIV risk among YMSM to accomplish this objective. The NHBS YMSM supplement would include qualitative ethnographic research, quantitative survey research, and HIV testing, conducted from June 2012 to February 2013. The quantitative survey would include questions in four domains: demographics, HIV risk behaviors, HIV testing, and the use of HIV prevention services. DOHMH will sample members of the target population through two methods, including venue-based sampling and respondent-driven sampling or, as an alternative to either one of these methods, a third method of participant recruitment based on the results of formative research. DOHMH will complete surveys with a minimum of 600 YMSM (300 for each of the two selected sampling methods). DOHMH will conduct HIV testing to estimate HIV prevalence (through Western Blot diagnostic testing) and HIV incidence (through dried blood spots tested at the CDC laboratories) among YMSM. Throughout the research study, DOHMH will collaborate with community partners including the local HIV Prevention Planning Group, HIV Planning Council, and federally-funded community-based organizations. DOHMH will also collaborate with local researchers with knowledge of the target population and with expertise in qualitative research methods to conduct formative qualitative research on YMSM to inform and support the main data collection phase. Finally, DOHMH will conduct evaluations of the research study to refine the methods of HIV behavioral surveillance focused on YMSM and will conduct analyses to describe the target population and to investigate specific research questions on HIV risk. PUBLIC HEALTH RELEVANCE: The young men who have sex with men (YMSM) supplement will enhance the National HIV Behavioral Surveillance System (NHBS) by including a young, vulnerable population of men who have sex with men (MSM). This will increase our knowledge about HIV risk in this group with direct relevance for prevention and service programs, and will enable the development and evaluation of sampling and other research methodologies that can be the basis for ongoing, systematic behavioral surveillance of YMSM.